Face Armatures

A rigid head made of plastic works best for stylized designs with a simpler look, but other puppet designs will call for a bit more mobility in the face. Because human and animal faces are often just as flexible a piece of design as the rest of the body, some puppet faces will be rigged with armature pieces to be animated. Posable paddles, wires, or other mechanisms can be built to simulate movement of the jaw, lips, brow, and eyebrows of the puppet face. In many cases, a movable face armature will be covered with a flexible material like foam latex or silicone. This will cause the surface of the face to bulge and stretch like real skin for the facial features that are manipulated underneath. Pulling and pushing on a jaw or an eyebrow paddle on the surface of the face creates a unique range of possible emotions for the animator. A few examples are illustrated here, ranging from studio productions to independent projects.

For the feature film $9.99, director Tatia Rosenthal conceived a system for achieving subtle flexibility in the faces of her puppets. Silicone faces were cast over a hinged chin for jaw movements, with a tiny slot for inserting replacement mouths for dialogue and paddles for eyebrow movements for extra expression. The face mechanisms for the armatures (Figure 3.82) were developed by Philip Beadsmoore. The overall effect given to the puppets is that of being able to combine lip sync that matches each syllable with subtle vertical movements in the jaw. When a character’s mouth goes into a long “ah” or “oh” vowel sound, for example, the jaw can drop just as it would on a real human face. This gives a subtle touch of flexibility that couldn’t be achieved with a static head made of plastic. For the realistic design of these puppets and the feel of the film, the puppet design serves the aesthetic purpose it sets out to do for this particular independent feature film (Figure 3.83).

feature film $9.99. (Courtesy of Tatia Rosenthal/Here

Media/Regent Releasing.)

Another complex face armature was designed for a puppet of the character Uncle Creepy for a recent stop-motion project for New Comic Company directed by Stephen Chiodo. Based on a sculpt by Chiodo himself, the Uncle Creepy puppet was built primarily on a ball-and-socket armature built by John Deall, with silicone-cast skin for the hands and head (Figure 3.84). Underneath the head was an epoxy skull, complete with a jaw piece on a ball joint that could pose open and closed, as well as left to right for a crooked jaw effect. For additional mouth shapes and brow movements, paddles were designed for the upper lip and the eyebrows (Figure 3.85). For the project’s animators, Kent Burton and Justin Kohn, the Uncle Creepy puppet allowed a strong sense of control in the face to complement the rest of the body animation. For the lip sync, movement of the jaw is wider or narrower depending on whether a syllable is accented; it would be opened wider for long vowel sounds and accents in the phrasing (Figure 3.86). To accentuate the fluidity of the actual puppet’s animation, certain mouth shapes that required a pucker or tightening of the lips were re-sculpted photographically using After Effects filters. This gives the puppet a unique sense of lip sync that is completely believable when combined with the aesthetics of the entire project. The amazing Uncle Creepy Returns film can be found and studied at http://www.youtube.com/user/creepyuniverse.

Stephen Chiodo/New Comic Company.)

(Courtesy of Stephen Chiodo/New Comic Company.)

Another example of an armature with face controls has been designed by independent animator Dave Hettmer from Michigan, who has worked on stop-motion and miniature effects for films such as Frostbiter: Wrath of the Wendigo and Army of Darkness. For his personal stop-motion project Road Rage, Dave designed frog and snail puppets out of foam latex cast out of plaster molds. The frog (Figure 3.87) is built on an aluminum wire armature (Figure 3.88), and his top and bottom mouth pieces is built out of two 1/8-inch 6061 plates (a typical grade found at hardware stores). Around the mouth plates are lip mechanisms built out of 24-gauge steel florist’s wire, which allows for pinching into certain shapes for “oo” or other syllables.

The snail armature (Figure 3.89) is built on a ball-and-socket neck piece, with a head made of 6061 aluminum blocks filed and ground to shape using a grinding wheel. The snail’s dialogue movement is achieved with looped pieces of steel florist’s wire, which fits inside the bottom jaw and is bent into various mouth shapes (Figures 3.90 to 3.93). The range of movement in the snail’s mouth is similar to the open-and-close motion of a hand puppet, but with some additional mouth shapes made possible by the multiple wires. To further accentuate accents in the dialogue, the eyes are attached to bendable wires clamped into the head with set screws. Being able to extend the eye-stalks up and down to the rhythm of the dialogue uses the snail’s design to further accentuate the character of his movement (Figure 3.94). The eyes themselves are plastic beads fixed in place, and the pupils are made of thin latex painted with black acrylic paint and Pros-Aide. To make the pupils for both puppets, Dave dipped eye-sized balls in latex for a thin skin that would fit perfectly over the curvature of the ball. Then, he cut out several copies of each pupil, which measured only 4 millimeters in diameter. These tiny pupils are stuck to the eyeballs with petroleum jelly on the back for easy sliding around, and the eyelids are added using clay replacement pieces. In addition to the eye and mouth movement, the ball-and-socket joints in the snail’s neck allow for smooth animation of the rest of his body to match extreme accents in the dialogue where they are needed. By combining different materials together for the neck, eyes, and controllable mouth shapes, the end results allow for puppets that are designed specifically for great animation and range of expression. Examples of Dave’s animation and other work can be found at his website (http://www.hettmerfx.com) and on YouTube (http://www.youtube.com/user/hefflesniggener).

Another example someone who has used an advanced method for achieving effective face movements is independent animator Ron Cole from New York, who burst onto the stop-motion scene with an innovative, award-winning short film called In the Fall of Gravity (Figure 3.95). The puppets for his film move with a unique sense of realism and fluidity that is spell binding in its execution, design, and aesthetic beauty. His work amazed many people in the stop-motion community upon seeing the film’s trailer on Ron’s blog site and the StopMotionAnimation.com message board. In the Fall of Gravity is a philosophical dialogue between the wizard Isomer (Figure 3.96) and his apprentice Trevor Verity. Each puppet’s facial expressions and lip sync are achieved through a unique blend of traditional stop-motion puppet animation and a cable control system attached to the puppet’s face and connected to an external control box (Figure 3.97). By turning dials on the box, cables attached from the dials run up through the puppet’s body into points inside the face (Figures 3.98 and 3.99). The faces are cast in flexible urethane rubber that stretches and bulges into subtle changes created by the cables, and these changes can be manipulated incrementally frame by frame for a certain naturalistic effect.

I asked Ron to share some thoughts about the evolution of his puppet designs, how they work, and the challenges involved in creating them:

I had a previous background of 20 years in stop-motion, live-action puppets, and cable controls. Part of my inspiration for getting into cable controls came from a shot Rick Baker did for the 1976 remake of King Kong, where Kong drew a breath and blew on the actress after she fell in the waterfall. The cable control technology had been well established further on films like American Werewolf in London and E.T. This other work for live-action monster effects had been done with different heads that each did one part of the facial movement. E.T. was one of the only characters made to fully speak, and he would speak in slow motion. My challenge was to miniaturize it and do it frame by frame. With this kind of cable system, there are always tension problems to overcome, and the cables need to be delicate but strong. The skin is paper thin at times, and so many things occur about what nature actually does. For example, not only do lips stretch open, but often there are moments where you need open jaws with the lips closed in order to get many different shapes which happen rather frequently. It’s easy to have cables pulling the lips apart, but not pushing, so I needed to have metal pieces inside the lips to push them closed. I also needed to make the world’s smallest hinge for a metal piece that had to bend outwards.

A big challenge with this system, which I learned with my first puppet, Trevor, is that the cables would tend to break in the control box end. Because they had tension on them, they would get sucked inside the tube and would not be retrievable, unless I opened up the puppet to get the cable out. So, for Isomer, I built a junction box (Figure 3.100) between the control box and the puppet, and split the cables into two halves. Inside the box, the wires were bundled very close together, so I created a map under the lid to indicate which hole and which wire goes where.

On the control box side, there are two types of controls: ones that only pull the cable and others that have a dual function. The dual function controls are only the eyebrows; turning the knob left brings the brow down, and right brings them up. I managed to do that by finding a way to attach two cables to the same controller, which both pull, but in opposite directions. The cables for the face are controlled by 16 dials (Figure 3.101), which achieve the following functions:

1) Outside left eyebrow up and down 2) Inside left eyebrow up and down 3) Inside right eyebrow up and down 4) Outside right eyebrow up and down 5) Left crow’s feet up 6) Right crow’s feet up 7) Bridge of nose up8) Top lip up 9) Bottom lip down 10) Lips form "O" toward top teeth11) Lips form "O" toward bottom teeth12) Left side smile13) Right side smile 14) Left side frown 15) Right side frown 16) Jaw open

When animating realistic dialog, the face moves as a whole in order to portray both the words and expressions that give them further meaning (Figures 3.102 to 3.107, showing various expressions for Isomer). That's also true even when the character isn't speaking at all. The human face is obviously the most expressive part of our bodies and is virtually always in motion expressing moods, thoughts, ideas, comfort, and concerns. A personal rule of mine about animating is the idea that “stillness equals death.” Even if only in the tiniest increments possible, I made my best effort to keep every part of a puppet moving at all times.

Outside of the facial controls, the animation for everything else on the body, eyes, and eyelids is done by touching the puppet. I also have a clay tongue that slips into the mouth when I need it, as there is no point in mechanizing that. Isomer has replacement plastic eyelids, and Trevor’s eyelids are just clay. My cable technique will continue to be refined, and my dream is to eventually fit the control box inside the puppet.

A detailed tutorial for the inner workings of Ron’s cable control system can be found on his blog (http://wobblytripod.blogspot.com), as well as other behind-the-scenes looks at his work and how to order a copy of In the Fall of Gravity.

Replacement Faces and Rapid Prototyping

Another emerging technology being implemented into various aspects of stop-motion puppet and set construction is rapid prototyping, or 3D printing. The basic concept behind this technique is to create a 3D computer model and have it printed out as a physical replica. The technology behind rapid prototyping has many other uses and implications in itself, but the film Coraline helped put it on the map for use as an animation technique. The area of the film where it was used the most was the facial animation on certain main characters. The faces on characters like Wybie, Coraline’s Mother, Other Mother, and Coraline herself consisted of thin replacement masks that were removed and replaced for each frame of the animation.

Replacement animation for facial expressions is a technique that has been around since the very beginning of the stop-motion medium. It likely grew out of the logic behind hand-drawn animation, where every frame consisted of a separate drawing that was different than the one before it, and each drawing was replaced under the rostrum camera for shooting. Adapting this idea to stop-motion meant that every frame would consist of a separate face that was replaced for each frame. The earliest known use of replacement faces appears to be from the MoToy Comedies by American filmmaker Howard S. Moss in 1917. Most of these films are lost, but the few that exist feature a dopey character with exaggerated facial expressions (Figure 3.108). A small number of in-between faces would help to transition from one key expression to another for a caricatured effect. Later evidence of replacement faces is found in the Kinex Studio short films from 1928 to 1930, in the characters of Snap the Gingerbread Man and a recurring witch character (Figure 3.109). It is not entirely clear what materials were used to create the faces for the characters in these early films, but they appear to be sculpted in clay and then either baked or molded. To keep the consistency between faces, it is likely that a clay sculpt was made and cast out in a mold, and then a tiny transitional change was made in the sculpt for each sequential cast. These puppets usually had only one or two in-between faces between each expression. The New Gulliver in 1935 also used the technique, with a decidedly more crude clay appearance.

George Pal took the idea of replacement animation to another level by carving entire puppets out of wood and replacing the whole puppet for each frame. Later feature films produced by Pal would re-visit the replacement face technique with varying complexity and design ideas, including Wah Chang’s work on Tom Thumb and The Wonderful World of the Brothers Grimm. Commercials for the Pillsbury Doughboy and Speedy Alka-Seltzer brought replacements to TV production, and in more recent years the technique re-surfaced in some of the puppets for The Nightmare Before Christmas and James and the Giant Peach. In these cases, faces were sometimes rigged with magnets on the back to help them snap onto the head and keep them registered in place. Obviously, it was very important to have a numbering and labeling system for the different faces because many of them would only have a subtle difference in appearance. The advantage to replacement faces has always been the ability to achieve a fluidity and range of expression that is not possible with just one static head. The challenge behind them is the incredible amount of work involved in sculpting each individual piece and in keeping them properly registered on screen. The materials used, whether clay or plastic, would often warp over much time and re-use on set, which would cause major problems in keeping their look consistent.

The advancement in technology using replacement faces for Coraline bridged the gap between modern computer animation and bringing the precision it offered into a physical stop-motion universe. Animator and sculptor Martin Meunier, who had worked with director Henry Selick on previous stop-motion films, served as the facial animation designer and coordinated an entire rapid prototyping department for Coraline. The process started with traditional means before going digital. Facial expression changes and lip sync were designed and animated in 2D, and then key poses were sculpted as clay maquettes and scanned into the computer. The computer animated in-between positions, and entire animated face sequences were animated in CG. Each individual frame of the computer animation was exported as an STL (stereolithography) file and printed out on an Objet 3D printer (any one of three printers installed for the production). A 3D printer is basically like a photocopy machine that prints liquid resin on a flatbed in layers. Starting from the bottom of the model it is printing, an ultraviolet light cures each layer of resin as it prints until a hard replica of the model is completed.

Creative Studio in North Vancouver, Canada. (Photo by

Ken Priebe. Courtesy of Protodemon.)

Once printed, each modeled piece needs to have any extra support material removed, washed, scrubbed, and sanded, and then sent to the fabrication department for painting. Each character could have as many as 15,000 faces and up to 250,000 facial expressions available, all in perfect registration to each other. The variety in expressions was created by dividing the face into upper and lower halves (Figure 3.110), so that mouth movements and lip sync could be combined with eyebrow movements in many different combinations. The seam between the two halves of the face was removed in post-production by digital effects artists. In addition to the outer appearance of each face piece, inside were details like teeth, tongues, and uvulas, as well as a complex registration system to help the pieces fit together like a puzzle. The amount of sculpting and modeling work that went into the film was estimated to be the equivalent of nearly 30 years of traditional sculpting; rapid prototyping allowed this amount to be completed in about 18 months. It allowed them to experiment with using CGI against itself by printing it out into the real world and getting artists involved in the CG process. Overall, amid all the new technical precision and subtlety offered through this technology on Coraline, the end goal was for the audience to have an emotional connection with the characters.

bed. (Photo by Ken Priebe. Courtesy of Protodemon.)

The Objets used on Coraline are designed to operate like a printer or photocopier, with a head that moves back and forth to print out each layer of the model. There are similar machines under different brands that employ a similar process and print a plaster-like material that also have the ability to print in color. Other machines such as EnvisionTEC printers are operated by a 250-watt bulb inside the hub of the printer (Figure 3.111), which projects the computer data from each layer onto a metal plate on the outside. The metal plate rests in a bed of liquid resin, cures each projected layer, and raises up incrementally for each layer until the model is complete and suspended upside-down (Figure 3.112). Any negative space within the model can be supported by a mesh-like support material, which is generated within the actual computer modeling software. The plate and model are removed from the printer, and support material must be cut away from the model with a hot knife (Figure 3.113) and placed in a bath for cleaning.;

The future implications for this technology to continue stop-motion productions have yet to be seen, but there could be a great deal of potential for bridging the gap between stop-motion and the capabilities of CGI. For artists who specialize in modeling or sculpting in CG using tools like Maya, ZBrush or Mudbox, printing their work in 3D can be a valuable way to transition into stop-motion if they want the experience of seeing their art in actual space. The process also has implications for easing the duplication of objects that would otherwise be cast out of molds, likewise eliminating the issue of undercuts and inconsistencies that can occur. In addition to creative applications for animation, architectural models can be realized with a great amount of detail for possible aid in creating elaborate stop-motion sets (Figure 3.114). A world of ideas and options is opened up by CG modeling’s ability to create intricate details that would be very difficult to sculpt by hand, or to physically cast in a mold. In addition, these details can be duplicated in different scales. The effect of any 3D object growing, shrinking, or morphing is possible, simply by scaling or modifying the CG model and saving each change as a separate object to be printed. Entire replacement puppets can also be animated in the computer and printed out for each frame.

There is much that can still be explored, although for the average independent filmmaker, there is not only the issue of using it creatively, but also the issue of cost. The printers themselves have various ranges in cost and quality, and require a certain amount of space and material to support the maintenance behind them. The most convenient method for utilizing rapid prototyping technology is to enlist the services of a company that specializes in servicing prototypes based on your own 3D models. Companies like Shapeways (http://www.shapeways.com), Protodemon (http://www.protodemon.com), and others can provide this service if you upload your files to their websites and place orders for 3D printing production. They all typically have their own guidelines for submitting files and parameters for what they are able to produce. If you feel inclined to explore this technology and bring it further into the realm of stop-motion production, it can certainly achieve some effects that would be much more difficult to get otherwise. When used creatively and combined with a good dose of hand-crafted elements, there is a good realm of opportunity for bridging media and enhancing the art of stop-motion storytelling.

Replacement Animation Puppets

Scaling back to puppets of the simpler variety, the idea of replacement animation can also be achieved with materials much less costly than a 3D printer. I recently created a series of replacement figures for an animated logo sequence done in stop-motion. My friend and colleague Steve Stanchfield created a hand-drawn animation logo for his company, Thunderbean Animation (Figure 3.115), which provides animation services and produces DVDs of rare lost films from animation history. The logo starts with a lightning flash and the word “Thunder,” and then a happy animated bean comes in and places the word “Bean” into the title. Steve and I had been collaborating on a DVD full of rare stop-motion films called Stop-Motion Marvels, so I thought it would be cool if the logo was also done in stop-motion. Steve’s animation style is very rubbery, with lots of squash and stretch to the drawings, so I knew that replicating the same look in stop-motion would involve replacement puppets, much like the George Pal Puppetoons of the 1940s.

To create an understructure for the beans, I simply used tiny Styrofoam ball pieces for the top and bottom, glued them together with aluminum wire (Figure 3.116), and covered them in clay. Using the Styrofoam balls helped me keep the shapes relatively consistent from one puppet to the next and cut down on the weight. Studying Steve’s original animation told me I needed a pose where the bean’s eyes and mouth were closed, a slightly squashed version of the same expression (Figure 3.117), and at least one in-between position. I also needed a severely squashed pose for the anticipation (Figure 3.118) before he stretches up to place the words into the title (Figure 3.119), which also required separate puppets. Coming from the stretch was another in-between pose and a final pose to end him on as he stops to look upward and smile. I was able to streamline the original animation and simply re-use these basic shapes to get the effect I needed, without necessarily adhering to the need for that many replacement figures (Figure 3.120). For the arms and legs, I used small pieces of aluminum wire wrapped in black masking tape, and his hands and feet were made of sticky tack and white plasticine clay. I knew I would need a rig in the shot holding him up the whole time because the spindly legs would not be strong enough to hold him up on his own, and there would be several frames where he was in mid-air. A helping hand rig worked just fine for this, with the pincher on the end either holding a wire to stick into the puppet or sticking into the puppet itself. The rig was visible in every frame and later erased digitally in post-production.

[Figure 3.117] Basic shape for the bean as he enters the frame.

For the animation of these puppets, I set up a white poster board curved into a cove to create a plain white limbo space for the action to take place. This was lit with some ambient lighting to help soften the overall effect but still create a shadow under the puppets, emphasizing the fact this would be a 3D stop-motion version of the logo. I imported an image of the logo into my frame-grabbing software, and used it as an onion-skinned image to line up the framing of the shot and size of the puppet in the frame (Figure 3.121).

The logo would be composited into the shot later, and I wanted to match the exact framing as closely as I could. Once I got the framing right, I traced the edges of the logo with a dry-erase marker on the monitor to give me a reference point for when the puppet would actually make contact with the logo, and where he should step and land. Using all of this as a framework, I started animating (Figure 3.122).

Because of the different positions caused by the extreme squash-stretch movement and the fragility of the various puppets, in most cases I took the entire puppet apart between each frame. If the arms or legs needed to dramatically change position, I would take the wires out, bend them into shape, and stick them back in their new pose. The onion-skin feature was very useful for registering the extreme movements after removing the puppet from the set, and toggling the frames gave me an idea of how the arcs and movement were working. The whole sequence took me about 4 hours to shoot once it was all set up, and the end results were a happy stop-motion jumping bean!

Ken A. Priebe has a BFA from University of Michigan and a classical animation certificate from Vancouver Institute of Media Arts (VanArts). He teaches stop-motion animation courses at VanArts and the Academy of Art University Cybercampus and has worked as a 2D animator on several games and short films for Thunderbean Animation, Bigfott Studios, and his own independent projects. Ken has participated as a speaker and volunteer for the Vancouver ACM SIGGRAPH Chapter and is founder of the Breath of Life Animation Festival, an annual outreach event of animation workshops for children and their families. He is also a filmmaker, writer, puppeteer, animation historian, and author of the book The Art of Stop-Motion Animation. Ken lives near Vancouver, BC, with his graphic-artist wife Janet and their two children, Ariel and Xander.